Implantable pulse generators, such as pacemakers, defibrillators or implantable cardioverter defibrillators (“ICD”) provide electrotherapy to cardiac tissue via implantable cardiac electrotherapy leads. Delivery devices, such as delivery catheters or sheaths, serve as a conduit for such leads and aid in the placement of the leads in specific cardiac anatomies during implantation of the pulse generator. Upon placement of the lead, the delivery catheter is removed and care is taken to not disrupt the position of the implanted lead. Non-disruptive removal is also advantageous when the delivery devices are used to deliver other cardiac surgical devices, such as inner catheters, guidewires and other accessories.
A common technique for accomplishing the non-disruptive removal of the delivery device involves slitting or otherwise cutting the catheter over the lead using a small blade known as a slitter. A typical catheter used in this technique is designed such that the force required to slit the sheath is as low and as consistent as possible. However, the hub of the delivery catheter typically requires considerably more force to slit through than is required for the shaft. That is, when slitting the catheter, the user begins by generating enough force to slit through the hub. As the slitter transitions from the hub to shaft, this force is excessively high and results in an acceleration or jerk. In the context of an implantable cardiac lead, if this jerk is severe, it may tear the cardiac tissue or disrupt lead placement, which results in a major procedural delay. Similarly, disruption of other cardiac surgical tools, such as an inner catheter, may cause damage to cardiac tissue or major procedural delays.
There is a need in the art for a slittable delivery device for an implantable cardiac electrotherapy lead or other cardiac surgical tool that will reduce or eliminate the hub-to-shaft transitional jerk and reduce the potential for lead or cardiac surgical tool displacement or dislodgement during removal of a delivery device. There is also a need in the art for a method of manufacturing such a delivery device.